Pre-loaded delivery device with tri-fold proximal prosthesis attachment

ABSTRACT

A pre-loaded prosthesis delivery device is described. In one example, the prosthesis delivery device is pre-loaded with a single wire that allows the device to be tracked into place within a vessel and also facilitates cannulation of a branch vessel. The delivery device further comprises a prosthesis that is releasably coupled to a delivery catheter by using two attachment wires to secure the proximal end of the prosthesis to the delivery device in a tri-fold configuration.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional application No.62/128,705, filed on Mar. 5, 2015, and also claims priority to U.S.Provisional application No. 62/148,006 filed on Apr. 15, 2015, whichapplications are incorporated by reference herein in their entireties.

TECHNICAL FIELD

This disclosure relates to introduction systems for the delivery anddeployment of implantable medical prostheses. In particular, thisinvention relates to a stent graft delivery device or introducerpre-loaded with a guide wire that facilitates both device tracking andcannulation, with a tri-fold attachment mechanism to couple theprosthesis to the delivery device.

BACKGROUND

The introduction and deployment of a medical device such as a stent orstent graft into a patient is a well-known procedure. The introducer mayinclude an external manipulation section or handle, an inner catheterthat may accommodate a guide wire, a medical device carried by the innercatheter, a nose cone dilator at the proximal end of the inner catheterand a retractable outer sheath. The medical device is generally coupledto the proximal end of the introducer. During deployment, the medicaldevice is released from the introducer, first by retraction of thesheath, and/or the operation of other release mechanisms to facilitateexpansion of the device in the body vessel.

Descending thoracic aortic aneurysms and dissections are often treatedby placing a stent graft in the affected region of the vessel. In someprocedures, the affected region (i.e., the location of an aneurysm ordissection) necessitates creating a seal with the stent graft at thelocation of a branch vessel extending from the main vessel, such as theleft subclavian artery extending from the aortic arch, for example. Insuch cases, a fenestrated and/or branched graft may be used to maintainpatency of both the main vessel and the branch vessel.

Accordingly, it may be desirable and advantageous to provide a stentgraft delivery device or introducer that is pre-loaded with a singleguide wire which can facilitate the delivery of the stent graft to thedesired location within a vessel as well as the cannulation of one ormore branch vessels. It may also be desirable to releasably couple thestent graft to the delivery device with an attachment mechanismincluding a proximal tri-fold configuration.

SUMMARY

In one example, a prosthesis delivery device is disclosed. The deliverydevice comprises a delivery catheter having a proximal end and a tubularprosthesis releasably coupled to the proximal end of the deliverycatheter. The prosthesis has a proximal end, a distal end, a lumenextending between the proximal end and distal end, a sidewall of graftmaterial, an inner graft surface, an outer graft surface, and afenestration formed in the sidewall of the prosthesis. The deliverycatheter extends proximally through at least a portion of the prosthesislumen and through the fenestration to a location external of theprosthesis and adjacent a first point on the outer graft surface of thegraft at the proximal end. A first proximal attachment mechanismreleasably couples a second point on the proximal end of the prosthesisto the delivery catheter, wherein the second point is circumferentiallyspaced from the first point and a second proximal attachment mechanismreleasably couples a third point on the proximal end of the prosthesisto the delivery catheter, wherein the third point is circumferentiallyspaced from the first point in one direction and from the second pointin the opposite direction. The first and second proximal attachmentmechanisms draw the second and third points to the first point to formthree folds of graft fabric and wherein the folds extend about thedelivery catheter in a folded configuration such that the outer surfaceof the graft at least partially wraps around the delivery catheter.

In another example a prosthesis delivery device is disclosed. Thedelivery device comprises a delivery catheter having a proximal end anda tubular prosthesis releasably coupled to the proximal end. Theprosthesis has a proximal end, a distal end, a lumen extending betweenthe proximal end and distal end, a sidewall of graft material, an innergraft surface, an outer graft surface and a fenestration formed in thesidewall of the prosthesis. The delivery catheter extends proximallythrough at least a portion of the prosthesis lumen and through thefenestration to a location external of the prosthesis and adjacent afirst point on the outer graft surface at the proximal end of theprosthesis. A first proximal attachment mechanism releasably couples asecond point on the proximal end of the prosthesis to the deliverycatheter, wherein the second point is circumferentially spaced from thefirst point and a second proximal attachment mechanism releasablycouples a third point on the proximal end of the prosthesis to thedelivery catheter, wherein the third point is circumferentially spacedfrom the first point in one direction and circumferentially spaced fromthe second point in the opposite direction. The first and secondproximal attachment mechanisms draw the second and third points to thefirst point to form first, second, and third folds of graft fabric andwherein the folds extend about the delivery catheter in a foldedconfiguration.

In yet another example, a prosthesis delivery device is disclosed. Thedelivery device comprises a delivery catheter having a proximal end anda tubular prosthesis releasably coupled to the proximal end of thedelivery catheter. The prosthesis has a proximal end, a distal end, anda lumen extending between the proximal end and distal end and afenestration formed in a sidewall of the prosthesis. The deliverycatheter extends proximally though at least a portion of the prosthesislumen and through the fenestration formed in the side sidewallwall ofthe prosthesis. A first attachment mechanism releasably couples a secondpoint at the proximal end of the prosthesis to the delivery catheter anda second attachment mechanism releasably couples a third point at theproximal end of the prosthesis to the delivery catheter. The first andsecond proximal attachment mechanisms have a first configuration inwhich the proximal end of the prosthesis is coupled to the deliverycatheter and a second configuration in which the proximal end of theprosthesis is released from the delivery catheter.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 shows an example of an introducer located within a vessel.

FIG. 2 shows an example of an introducer located within a vessel and anexample of a branched stent graft deployed therein.

FIG. 3 shows the proximal end of the introducer of FIG. 2 with oneexample of a deployed branched stent graft having a catheter and a guidewire extending proximally through a portion of the stent graft and intoa channel formed in the nose cone dilator.

FIG. 4 shows the proximal end of an introducer with one example of adeployed fenestrated stent graft having a catheter and a guide wireextending proximally through a portion of the stent graft and into achannel formed in the nose cone dilator.

FIG. 5 shows the introducer of FIG. 3 where the catheter and guide wirehave been distally retracted out of the channel formed in the nose conedilator.

FIG. 6 shows the introducer of FIG. 4 where the catheter and guide wirehave been distally retracted out of the channel formed in the nose conedilator and a secondary guide wire remains in a straight lumen of thenose cone dilator.

FIG. 7 shows an enlarged view of a nose cone dilator with a catheter andguide wire extending through a curved channel and a straight lumenextending through the nose cone.

FIG. 8 shows one example of a conventional introducer.

FIG. 9 shows an introducer with a deployed branched stent graft and avariable diameter dilator tip in an expanded-diameter configuration.

FIG. 10 shows the introducer of FIG. 9 with a deployed branched stentgraft and a variable diameter dilator tip in a reduced-diameterconfiguration.

FIG. 11 shows another example of a variable diameter tip in areduced-diameter configuration with a single resilient elongated member.

FIG. 11A shows another example of a variable diameter tip in areduced-diameter configuration with two resilient elongated members.

FIG. 12 shows the variable diameter dilating tip of FIG. 11 in anexpanded diameter configuration.

FIG. 13 illustrates a dilator and a delivery sheath that may be placedwithin a vessel during a procedure utilizing a cartridge technique.

FIG. 14 shows another example of an introducer with a peel-away sheaththat may be tracked through the delivery sheath of FIG. 13 in aprocedure utilizing a cartridge technique.

FIG. 15 shows an example of a stent graft coupled to the proximal end ofan introducer and partially constrained by an introducer sheath.

FIG. 16 is a perspective view of the proximal end of the introducer withthe stent graft releasably coupled to the introducer using a tri-foldconfiguration.

FIGS. 17-22 illustrate one example of a method for using two wires as aproximal attachment mechanism to create a tri-fold configuration at theproximal end of a stent graft to releasably couple the stent graft tothe introducer.

FIG. 23 shows the introducer of FIG. 15 with the stent graft covered bya sheath and being tracked over a guide wire in a curved vessel.

FIG. 24 shows the introducer of FIG. 23 with the sheath fully withdrawn.

FIG. 25 shows the introducer of FIG. 24 with the proximal attachmentwires removed to release the proximal tri-fold configuration anduncouple the proximal end of the stent graft from the introducer.

FIG. 26 shows an example of an introducer assembly with a sheath taperedradially inwardly at the proximal end to mate with a nose cone dilator.

DETAILED DESCRIPTION

The present disclosure relates to a delivery device or introducer fordelivering a prosthesis such as a radially expandable stent graft withina human or animal body for repair of damaged vessels, ducts, or otherphysiological pathways and systems. In the present disclosure, the term“proximal” refers to a direction that is away from a physician during amedical procedure, while the term “distal” refers to a direction that isclosest to the physician during the procedure. In addition, likereference numbers throughout the various drawings designate similarstructure.

FIG. 1 shows an example of an introducer that has been tracked over aguide wire to a desired location within a curved vessel. In FIG. 1, thecurved vessel 1 is the thoracic aorta. The thoracic aorta includes theascending aorta 2 extending from the aortic valve 4 of the heart of thepatient, the thoracic arch 6 and the descending aorta 8. Three brancharteries extend from the main artery (the thoracic arch 6) including theinnominate artery 10, the left carotid artery 12 and the left subclavianartery 14. As shown, an aneurysm 16 has developed just distal of theleft subclavian artery 14. The space 17 between the most proximalportion of the aneurysm 16 and the left subclavian artery 14 may, insome cases, be relatively short as shown in FIG. 1, and in other casesthe space may be longer. Depending on the patient's unique anatomy andthe location of the aneurysm 16, it may be necessary to extend theproximal end of a stent graft deployed in the vessel lumen 20 to an areaor location that is proximal of the left subclavian artery 14 but distalto the left carotid artery 12. In doing so, blockage of some or all ofthe left subclavian artery 14 by the body of the stent graft may result.Accordingly, it may be advantageous to provide an introducer that ispre-loaded with a guide wire and a stent graft to facilitate cannulationof a branch vessel (such as the left subclavian artery 14) to thereforemaintain/restore patency to the main vessel and branch vessels. Asdescribed herein, the stent graft carried on the introducer ispreferably pre-cannulated with the guide wire. This single guide wirefacilitates tracking of the introducer within a vessel, cannulation ofthe stent graft carried on the introducer and also allows cannulation ofone or more of the branch vessels during use.

As partially shown in FIG. 1, an introducer 18 has been advanced intothe lumen 20 of the vessel 1. In one example, the introducer 18 includesa retractable or removable sheath 22 and a secondary catheter 74. One ormore guide wires 26 may extend through the lumen of the secondarycatheter 74. The secondary catheter may be straight and/or it may have acurve imparted to a portion of it. For example, the secondary catheter74 may be curved at a proximal end, with the curve of the secondarycatheter generally corresponding to the outer or greater portion of thecurve of the aortic arch 6.

The guide wire 26 may first be introduced into the vessel 1 and theintroducer 18 then tracked over the guide wire 26 to a desired positionwithin the vessel. Alternatively, the guide wire 26 may be pre-loadedwithin the secondary catheter 74 of the introducer, and thereby insertedinto the vessel simultaneously with the introducer 18, or in yet afurther example, the guide wire 26 may be inserted through the secondarycatheter 74 of the introducer 18 and into the vessel 1 after theintroducer has been at least partially positioned in the vessel 1. Theintroducer 18 also includes a nose cone dilator 28 extending proximallyfrom the proximal end of the delivery catheter 66. The nose cone dilator28 may be tapered and/or flexible to present an atraumatic tip.

As shown, the guide wire 26 extends through the secondary catheter 74 ofthe introducer 18, through at least a portion of the nose cone dilator28 and has been extended further proximally to extend from the tip 30 ofthe nose cone dilator 28. As such, the guide wire 26 may facilitatetracking of the delivery device for placement, adjustment and movementof the delivery device 18 within the vessel 1. The proximal tip 32 ofthe guide wire 26 may have a curved (pig-tailed end) atraumatic tip soas not to pierce or damage the walls of the vessel lumen 20 and/or theaortic valve 4. The introducer 18 can be substantially straight or itmay have a curved configuration imparted at its proximal end asdescribed in U.S. Pat. No. 8,394,135, which is incorporated by referenceherein. The nose cone dilator 28 also may be straight or curved, asshown in FIGS. 9 and 10 of U.S. Publication Application No. 2011/0125244and in U.S. Pat. No. 7,611,529, which are both incorporated by referenceherein. Prior to and during delivery of a prosthesis, such as a stentgraft 34, the sheath 22 extends proximally to cover the stent graft 34carried on introducer 18 to hold the stent graft in a radially inwardlycontracted delivery configuration. The sheath 22 may extend proximallyto cover at least the distal end of the nose cone dilator 28 asillustrated in FIG. 1.

FIG. 1 shows an example of an introducer 18 tracked over guide wire 26to a location within a vessel 1, with the stent graft 34 still coveredand held in a radially inwardly contracted delivery configuration bysheath 22. FIG. 2 shows the introducer of FIG. 1 within the vessel 1after the sheath 22 has been distally retraced allowing the stent graft34 to deploy from the introducer 18 and become expanded within thevessel 1 at the site of aneurysm 16. As shown, the stent graft 34 has aproximal end 36, a distal end 38, a proximal opening 40, a distalopening 42 and a tubular body 44 extending between the proximal 36 anddistal 38 ends to define a graft lumen 52. The stent graft 34 may be agenerally singular tube-like configuration with an internal branch 48extending within the lumen 52 of the graft body 44 as illustrated inFIG. 2, although other configurations are also contemplated. Forexample, the stent graft 34 may be a fenestrated stent graft (whereinone or more openings or fenestrations are formed in the graft body 44)and/or a bifurcated stent graft (with first and second legs extendingfrom the main graft body).

A series of stents 46 may be attached to the graft body 44 and extendalong all of, or at least part of, the length of the stent graft 34. Anexposed anchoring stent (not shown) with one or more barbs for attachingthe stent graft to a vessel wall may extend from the proximal end 36 ofthe graft body 44 as described in U.S. Publication Application No.2012/0277848, which is incorporated by reference herein. The stents 46may be sutured to the graft material or held to the graft material inother known ways. The series of body stents 46 may be internal orexternal to the graft body 44, or both. For example, one of the stents46 near the proximal end 36 and/or the distal end 38 of the stent graft34 may be an internal sealing stent while the remaining body stents 46are external to the graft body 44. Any one or more of the stents 46 maybe provided with barbs that extend from the stent inside the tubulargraft body, through the graft material to engage the vessel wall.Radiopaque markers (not shown) may be placed on various parts of thestent graft 34 to aid the user in positioning the stent graft duringdeployment.

Stents 46 may be zig-zag shaped as shown in FIG. 2, although other stentconfigurations are known and may be used alone or in combination withthe zig-zag stents 46 and/or have other configurations as known in theart. The stents may be constructed of a self-expanding shape memorymaterial, such as Nitinol, or they may be balloon expandable, or acombination of both depending on the particular characteristics desiredof the stent graft.

As shown in FIG. 2, stent graft 34 is a branched stent graft that hasbeen deployed in the aorta 1, having a series of self-expanding stents46 extending along the length of the graft body 44. In this example, thebranch 48 is an internal branch. In other words, the body 50 of thebranch 48 extends within the lumen 52 of the stent graft 34. The branch48 has a proximal end that extends from an aperture 56 formed in thesidewall of the graft body 44 and has a distal open end 54 that opensinto lumen 52 of the stent graft 34.

FIG. 3 and FIG. 4 illustrate an introducer 18 with one example of a nosecone dilator 28 and a fully deployed stent graft 34. The nose conedilator 28 has a distal end 58 and a proximal end 60 and a sidewall 62extending between the proximal and distal ends. Nose cone dilator 28 mayhave a straight or substantially straight lumen 64 formed within andextending the length of the nose cone dilator 28 between the distal end58 and proximal end 60. The straight lumen 64 may be configured toreceive one or more guide wires and/or catheters there through. In oneexample, straight lumen 64 receives at least a proximal end of deliverycatheter 66 but does not receive a guide wire. The delivery catheter 66may be straight and/or it may have a curve imparted to a portion of it.For example, the delivery catheter 66 may be curved at a proximal end,with the curve of the secondary catheter generally corresponding to theouter or greater portion of the curve of the aortic arch 6.

Nose cone dilator 28 may also have a channel 68 formed within andextending through a portion of the length of the nose cone dilator 28from the proximal end 60 and to the aperture 70 formed in the sidewall62. The channel 68 may be at least partially curved and extend from theproximal end 60 of the nose cone dilator 28 and exit from the nose conethrough the sidewall 62 of the nose cone dilator at aperture 70, asshown in FIG. 4. In one example, channel 68 may extend substantiallylongitudinally for a distance (i.e., substantially parallel to straightlumen 64) and then curve at its distal end to exit the sidewall 62 ofthe nose cone dilator 28 through aperture 70 at a location approximatelymidway between the proximal end 60 and distal end 58 of the nose conedilator 28 as shown in FIGS. 3 and 4. However, the curved channel mayexit the nose cone dilator 28 either closer to the proximal end 60 orcloser to the distal end 58. In another example, the channel 68 may havea curve imparted to its entire length or may have a helical shapeimparted to it.

In an alternative example (not shown), the curved channel 68 may be inthe form of an elongated opening or slot extending from the aperture 70formed in the sidewall 62 of the nose cone dilator 28 towards theproximal end 60. The channel or slot may be straight or curved or acombination thereof, and extend partially or, alternatively, extend allthe way to the proximal end 60 of the nose cone dilator 28. In yet afurther example, a groove (not shown) formed in the surface of the nosecone sidewall 62 may be used in place of the curved channel 68. Thechannel 68 (and/or slot or groove) may extend partially and/or fully ina proximal direction from a point of origination (such as aperture 70and/or the beginning of the groove) towards the proximal end 60 of thenose cone. The channel 68 (or slot or groove) is preferably shaped andconfigured to receive at least a portion of the guide wire 26 and/or thesecondary catheter 74 therein.

In another example, either alone or in combination with the above, atrigger wire (not shown) may also be provided to constrain the proximaltip of the guide wire 26 and/or the secondary catheter 74 against orwithin the nose cone dilator 28. More specifically, one or more triggerwires may be used to retain the guide wire 26 and/or the secondarycatheter 74 within the curved channel 68 (or within the above-describedalternatives, including the elongated opening, slot or groove formed inthe nose cone dilator 28). The one or more trigger wires may pass overthe secondary catheter 74 (and/or the guide wire 26 extending throughthe secondary catheter 74) at one or multiple points along its lengthand secure it to the nose cone dilator 28. Thus, when the triggerwire(s) is removed, the secondary catheter 74 (and guide wire 26) arefreed from the nose cone dilator 28 and can then be manipulated by theuser to make any necessary exchanges, including, but not limited tocannulating a side vessel (such as the left subclavian artery) extendingfrom the aorta 1. When only trigger wire(s) are used to secure thesecondary catheter 74 to the nose cone dilator 28 (and the secondarycatheter 74 is not constrained within the curved channel 68 orabove-described slot), it may not be necessary to distally retract thesecondary catheter 74 to free it from a constrained configuration withinthe channel 68. Instead, removal of the trigger wire(s) will free thesecondary catheter 74 from the nose cone dilator 28 so that it isavailable for further manipulation by the user.

Secondary catheter 74 can be preloaded with guide wire 26 extendingthere through. Alternatively, guide wire 26 may first be inserted intothe vasculature and the introducer 18 then tracked over the guide wire26, through secondary catheter 74, and into position within the vessel.In a non-limiting example, one procedure for introducing the introducer18 into a patient is by means of the well-known Seldinger technique, inwhich a guide wire 26 is first inserted percutaneously into a patient'svasculature via a needle (not shown). The introducer 18 is insertedpercutaneously and endoluminally into the patient, by tracking it overthe guide wire 26, which acts to guide the introducer 18 through thevasculature up to the treatment site.

In one example, the straight lumen 64 and curved channel 68 create a ‘Y”shape within the nose cone dilator 28. In other words, as showngenerally in FIGS. 5 and 6, the straight lumen 64 lies in a relativelystraight line from the proximal end 60 to the distal end 58 of the nosecone dilator 28 and the curved channel 68 intersects the straight lumen64 at some point between the proximal end 60 and the distal end 58 ofthe nose cone dilator 28 to generally form a “Y” configuration. In oneexample, the curved channel 68 intersects the straight lumen 64 abouthalf way between the proximal end 60 and the distal end 58 of the nosecone dilator 28, although, the channel 68 may intersect the straightlumen 64 closer to the proximal end 60 and/or closer to the distal end58 of the nose cone dilator 28.

As shown in FIGS. 3 and 4, the stent graft 34 carried by the introducer18 can be pre-loaded with the guide wire 26. In one example, the guidewire 26 can extend proximally through the lumen 52 of the graft body 44,into the distal end 54 of the internal branch 48 and exit out of thebranch 48 at proximal branch opening 56. The proximal tip 32 of theguide wire 26 can extend through channel 68 of the nose cone dilator 28and into the proximal end 60 of the nose cone dilator 28. As shown inFIGS. 1 and 2, the guide wire 26 can, in use, be proximally advanced allthe way out of the proximal end 60 of the nose cone dilator 28.

Secondary catheter 74 may be coaxial with at least a portion of theguide wire 26. In one example, the secondary catheter 74 is alsopre-loaded within the introducer 18, such that the secondary catheter 74is coaxial with and extends proximally over the guide wire 26, throughthe lumen 52 of the graft body 44, into the distal end 54 of theinternal branch 48. The secondary catheter 74 then exits out of thebranch 48 at proximal branch opening 56. As FIG. 2 shows, the proximalend 76 of the secondary catheter 74 can be tucked into and held withinthe curved channel 68 of the nose cone dilator 28. As shown in FIGS. 3and 4 (and shown in greater detail in FIG. 7) the curved channel 68 (168of FIG. 7) may have a substantially constant inner diameter along itslength, and near the proximal end 60 of the nose cone dilator 28, theinner diameter of the channel 68 (168) becomes narrowed at point 69. Inthis way, the secondary catheter 74 (174) can advance proximally throughthe channel 68 (168) to the proximal end 60 of the nose cone dilator 28but it cannot advance through the narrowed inner diameter portion 69 ofthe channel 68. While the guide wire 26 (126) may pass through thenarrowed diameter portion 69 of the channel 68, the secondary catheter74 cannot pass through this narrowed diameter portion 69 of the channel68 and is therefore prevented from extending proximally out of theproximal tip 30 (130) of the nose cone dilator 28.

As shown partially in FIG. 1, the delivery catheter 66 may extendproximally from an external manipulation handle section or distal end ofthe introducer 18 (identified as reference number 100 in FIG. 8) throughthe lumen 52 of the graft body 44 and into the straight lumen 64 of thenose cone dilator 28 to secure the nose cone dilator 28 to the proximalend of the delivery catheter 66. The delivery catheter 66 may terminatewithin the lumen 64 near the distal end 58 of the nose cone dilator 28,or alternatively, the delivery catheter 66 may extend further into thelumen 64 and terminate at a point closer to the proximal end 60 of thenose cone dilator 28.

As shown in FIGS. 1 and 2, the guide wire 26 advantageously serves as ameans to track the introducer 18 to a desired location within the vessel1 while also pre-cannulating the branch 48 of the stent graft 34 with asingle wire 26. In other words, introduction of the introducer andcannulation of the branch 48 may be combined through the use of a singleguide wire 26, and this same guide wire may then be further manipulatedduring use to cannulate one or more branch vessels extending from themain vessel.

In one example, as FIG. 1 shows, a guide wire 26 can be insertedpercutaneously and advanced proximally through a vessel. Next, theintroducer 18 containing a prosthesis (such as a stent graft 34 held ina radially compressed delivery configuration under a sheath 22) can beadvanced over the guide wire 26. When the prosthesis is in a deploymentposition within a vessel lumen 52, the sheath 22 can be withdrawn andthe stent graft 34 can be deployed by one or more known methods. Forexample, following sheath retraction, one or more trigger wires ordiameter reducing ties (wires 442, 444 described in detail below inconnection with FIGS. 15-25) at the proximal end 36 of the stent graft34 and/or the distal end 38 of the stent graft, or both ends, can beremoved allowing the stent graft 34 to radially outwardly expand anddeploy from the introducer 18. With the secondary catheter 74 and/or thedelivery catheter 66 having a curve imparted to at least a proximal endor portion of it (which curve generally corresponds to the outer curveof the aortic arch 6) the secondary catheter 74 and/or the deliverycatheter 66 tend to sit adjacent to or on the greater curve of theaorta. With the stent graft 34 properly aligned with any one or more ofthe desired branch vessel(s), the stent graft 34 will preferably openaway from the delivery catheter 66 as it is unsheathed duringdeployment, further guaranteeing proper orientation within the vessel.

FIG. 4 and FIG. 6 show an example of the proximal end of an introducer18 with another example of a stent graft 78 carried on the introducer18. The stent graft shown in FIGS. 4 and 6 is a fenestrated stent graft78 that has been deployed within a vessel 1. Fenestrated stent graft 78has at least one fenestration or opening 80 formed in the sidewall ofthe graft body 44, but may not have the internal branch 48 as does thestent graft 34 shown in FIGS. 3 and 5. A guide wire 26 can be threadedproximally through the lumen 52 of the graft 78 and extended out of thelumen 52 through the fenestration 80. The proximal tip 32 of the guidewire 26 can then be threaded into and through the curved channel 68 ofthe nose cone dilator 28 as shown in FIG. 4. The guide wire 26 canadvance into the proximal end 60 of the nose cone dilator 28 and befurther advanced proximally all the way out of the proximal end 60 ofthe nose cone dilator 28.

As also shown in FIG. 4, the secondary catheter 74 is coaxial with atleast a portion of the guide wire 26. In one example, the secondarycatheter 74 is pre-loaded within the introducer 18, such that thesecondary catheter 74 extends proximally over the guide wire 26 andthrough the lumen 52 of the graft body 44, and exits out of the graftlumen 52 through fenestration 80. The proximal end 76 of the secondarycatheter 74 can be tucked into and held within the curved channel 68 ofthe nose cone dilator 28. The secondary catheter 74 can advance towardsthe proximal end 60 of the nose cone dilator 28 but it cannot advanceall the way out of the proximal end 60 of the nose cone dilator 28 dueto the narrowed inner diameter portion 69 of the channel 68. Like FIGS.1-3, the guide wire 26 of FIGS. 4 and 6 also advantageously serves as ameans to track the introducer 18 to a desired location within the vesselwhile also pre-cannulating the fenestration 80 with a single wire 26. Inother words, the stent graft 78 is pre-cannulated within the introducerby the guide wire 26 (i.e., the wire extends through the graft lumen andfenestration 80), and in addition, the guide wire allows the introducerto be tracked into place within a vessel while also allowing the wire tobe manipulated in use to cannulate a branch vessel, as described below.

FIGS. 5 and 6 show the guide wire 26 and secondary catheter 74 retractedpartially distally. The proximal tip 32 of the guide wire 26 has beenwithdrawn distally from the nose cone dilator 28. In addition, thesecondary catheter 74 has been retracted distally so that it is nolonger constrained within the channel 68 of the nose cone dilator 28. Inthis configuration, the user is free to manipulate the guide wire 26and/or the secondary catheter 74 to make any necessary exchanges, suchas, for example, to cannulate one or more of the branch vessels (such asthe left subclavian artery, left carotid and/or innominate artery)extending from the main vessel 1 as described generally below.

In one non-limiting example of use, the introducer 18 may be trackedover guide wire 26 to a desired stent graft position within a vessel 1as shown in FIG. 1. The sheath 22 can then be distally retracted toexpose the stent graft 34 (or stent graft 78 of FIGS. 4 and 6) and anytrigger wires or diameter reducing ties removed (such as wires 442, 444described below in connection with FIGS. 15-25) to allow the stent graftto release from the introducer 18 and deploy within the vessel 1. Atthis time, it may be desirable to cannulate a branch vessel, such as theleft subclavian artery 14, left carotid artery 12 and/or innominateartery 10, extending from the main vessel 1. To do so, the user maydistally retract the guide wire 26 and secondary catheter 74. Thisretraction will free guide wire 26 and secondary catheter 74 from thecurved channel 68 in the nose cone dilator 28 as shown in FIGS. 5 and 6.When the proximal end 76 of secondary catheter 74 is freed from thechannel 68, the guide wire 26 may then be manipulated by the user tocannulate a desired branch vessel. For example, the user may advance theguide wire 26 proximally and extend it into, and thereby cannulate theleft subclavian artery 14. If necessary or desired, a secondary stentgraft, such as an extension stent graft (not shown) loaded on to asecondary introducer (not shown) may be tracked over the guide wire 26and into the cannulated branch vessel to deliver and deploy theextension branch therein, thus restoring and/or maintaining patency tothe branch vessel.

FIG. 6 shows another example of an introducer 18 with a stent graft 78deployed from the proximal end of the introducer 18. The guide wire 26and secondary catheter 74 have been retracted distally out of thechannel 68 in the nose cone dilator 28. In one non-limiting exampleshown in FIG. 6, the nose cone dilator 28 may have a straight lumen 64extending between the proximal end 60 and distal end 58, configured toreceive a secondary guide wire 82 there through. If desired, thesecondary guide wire 82 can be advanced through the straight lumen 64and be extended out of the proximal end 60 of the nose cone dilator 28.In doing so, the nose cone dilator 28 will still have a guide wire 82extending there through to reinforce and constrain the positioning ofthe nose cone dilator 28 within the vessel lumen, while also maintaininga pathway for the introducer to be tracked over, even after guide wire26 and/or secondary catheter 74 has been partially or fully withdrawnfrom the body.

FIG. 7 shows an enlarged view of the nose cone dilator 128 with achannel or lumen 168 extending there through. As previously described,the nose cone dilator 128 has channel 168 that extends from the proximalend 160 of the nose cone dilator 128 and terminates at aperture 170formed in a sidewall 162 of the nose cone dilator. Curved channel 168can be configured to receive a guide wire 126 and a secondary catheter174 therein. As shown in FIG. 7, the channel 168 may have asubstantially constant inner diameter along its length, and near theproximal end 160 of the nose cone dilator 128, the inner diameter of thechannel 168 becomes narrowed at location 169. In this way, the secondarycatheter 174 can advance proximally through the channel 168 to theproximal end 160 of the nose cone dilator 128 but it cannot advancethrough the narrowed inner diameter portion 169 of the channel 168.While the guide wire 126 may pass through the narrowed diameter portion169 of the channel 168, the secondary catheter cannot pass through thisnarrowed diameter portion 169 of the channel 168 and is thereforeprevented from extending proximally out of the proximal tip 130 of thenose cone dilator 128.

FIG. 8 shows another example of a conventional introducer assembly 200.Introducer assembly 200 has a dilator tip 202 at its proximal end 210and an external manipulation section or handle at the distal end 100. Aflexible delivery catheter 216 extends from a location distal to thehandle 100 to the dilator tip 202. Although this introducer 200 can beused in any area of the vasculature, it is described here as being usedin the aortic arch.

As FIG. 8 and FIG. 9 show, an implantable prosthesis, such as a stentgraft 224, is carried on the delivery catheter 216 at the proximal end.A retractable introducer sheath 206 retains the stent graft 224 in aradially inwardly contracted delivery configuration on the deliverycatheter 216 and can be retracted during deployment. The introducer 200typically includes a pusher member 208 coaxial with at least a portionof the delivery catheter 216. The pusher member 208 extends proximallyfrom the distal end or handle portion of the introducer and terminatesat a location distal to the stent graft 224. In one example, theintroducer assembly 200 includes a guide wire 220 which passes throughthe delivery catheter 216 and the dilator tip 202. In use, theintroducer 200 can be tracked over the guide wire 220 to a desiredlocation within the vasculature during the delivery and deploymentprocedure.

The delivery catheter 216 may extend proximally through the lumen 218 ofthe stent graft 224 to the dilator tip 202. In another example, where afenestrated stent graft is used (such as the fenestrated stent graft 44shown in FIG. 4), the delivery catheter 216 may extend into the distalend of the stent graft, then outwardly through the fenestration 80formed in the sidewall of the graft and continue proximally to thedilator tip 202. In yet another example, where a branched stent graft isused (as shown in FIG. 9), the delivery catheter 216 may extendproximally into the distal end 228 of the stent graft 224, through thelumen of the internal graft branch 232 and continue out of the branch tothe dilator tip 202.

The dilator tip 202 is preferably tapered and smooth, therebyfacilitating atraumatic tracking and guiding of the introducer 200through tortuous vasculature to a desired location within a vessel. Inone example, the dilator tip 202 has a variable diameter. For example,the dilator tip 202 may be radially outwardly expanded, either partiallyor fully, during delivery of the stent graft 224. More specifically,when dilation is required, such as during insertion of the introducer200 into a patient, the tip may be partially expanded, or alternatively,fully expanded, so that the outer diameter of the dilator tip 202 is atits maximum size. The introducer 200 may then be tracked to its desiredposition within the vessel. After graft deployment, the dilator tip 202may be reduced in diameter to a smaller, radially inwardly contractedconfiguration. With the outer diameter of the dilator tip 202 reduced,the tip 202 can be retracted distally through the stent graft 224 forremoval from the vessel.

In another example, where the delivery catheter 216 extends through afenestration and/or side branch of the stent graft (such as, forexample, the fenestration 80 formed in the sidewall of the graft body 44of FIG. 4 and/or the branch 232 of the stent graft body 230 shown inFIG. 9), the reduction of the diameter of the dilator tip 202advantageously facilitates retraction and withdrawal of the tip 202through the lumen 218 of the stent graft body 230 and through thefenestration and/or through the graft side branch 232, while reducingthe risk of the tip 202 snagging on any portion of the stent graft(including the fenestration and/or the graft side branch 232) or fromsnagging on any other portion of the introducer 200 during retraction ofthe dilator tip 202 out of the body. If desired, the guide wire 220 maybe left in place within the main vessel 1, such as for furthermanipulation by the user to cannulate one or more branch vessels 10, 12and/or 14, and then retracted at a later time during a procedure

FIG. 9 shows an introducer 200 with a deployed branched stent graft 224and a variable diameter dilator tip 202 in a radially outwardlyexpanded-diameter configuration. FIG. 10 shows the introducer 200 ofFIG. 9 with a deployed branched stent graft 224 and a variable diameterdilator tip 202 in a radially inwardly contracted or reduced-diameterconfiguration. The dilator tip 202 shown in FIGS. 9 and 10 may be aballoon-like resilient element constructed of a material having radiallyexpandable and contractible properties. For example, the dilator tip 202may be formed of polyurethane, nylon, PEBAX® (polyether block amide),PVC, plastics, rubbers and/or other resilient materials or a combinationthereof. The tip 202 may have a substantially conical shape, sphericalshape or onion shape to facilitate atraumatic insertion in a body lumen.The diameter of the outer surface of the dilator tip 202 may vary alongits longitudinal length. For example, the tip 202 may have a proximaltaper and/or a distal taper, with the center portion of the tip 202having a greater diameter than the proximal and distal tapered portionswhen the tip 202 is in both the expanded condition and the contractedcondition. A lumen extends through the dilator tip 202 between itsproximal end 212 and distal end 214. The guide wire 220 extendsproximally through the lumen of the delivery catheter 216 and can beextended through the lumen of the dilator tip 202.

FIG. 9 illustrates the proximal end of an introducer 200 with a branchedstent graft 224 in a radially outwardly deployed configuration. Thestent graft 224 may have a proximal end 226, distal end 228 and atubular graft body 230 extending there between. One or more stents 234may be attached to the tubular graft body 230. Branched stent graft 224may have a proximal branch opening or aperture 236 located near theproximal end 226 of the stent graft 224. An internal graft branch 232extends distally from the branch opening 236 within the lumen 218 of thestent graft 224. The dilator tip 202 and delivery catheter 216 mayextend through the lumen 218 of branched stent graft 224. In one exampleshown in FIG. 9, the delivery catheter 216 and dilator tip 202 extendproximally through the lumen 218 of the stent graft 224, into the distalopening 238 of the branched stent graft 224 and exits the graft 224through the proximal branch opening 236. Although not shown, in anotherexample, a fenestrated stent graft can be used instead of a branchedstent graft, and the delivery catheter 216 would pass out of thefenestration instead of through the branch opening.

As mentioned above, the dilator tip 202 is moveable between a radiallyoutwardly expanded-diameter configuration (FIG. 9) and a radiallyinwardly reduced-diameter configuration (FIG. 10). During insertion ofthe introducer 200 into a patient, dilator tip 202 can be in an at leastpartially expanded configuration. Once a user has tracked the introducer200 into a desired location and deployed the stent graft 224, the outerdiameter of the dilator tip 202 may be reduced to a smaller diametercontracted configuration. The dilator tip 202 and delivery catheter 216may then be withdrawn from the patient by pulling distally on thecannula, such as by retracting handle 100 as FIG. 10 illustrates.

Several different mechanisms can be used to control the variablediameter of the dilator tip 202. In one example, the dilator tip 202 hasan inner cavity which can be filled with fluid, gel and/or gas as shownand described in U.S. Publication Application No. 2012/0109056, which isincorporated by reference herein. Another mechanism to control thediameter of the dilator tip 202 is by mechanical means. In one example,a flexible outer surface 240 covers an expandable structure such as, forexample, a series of members, fingers, cages, mesh and the like whichcan be mechanically expanded and contracted. As the structure isexpanded and contracted, the flexible outer surface 240 radially expandsand contracts along with it, thus providing the user with control overthe diameter of the dilator tip 202.

FIG. 11 shows one example of a mechanically expandable variable diameterdilator tip 202 in a reduced-diameter configuration. FIG. 12 shows thevariable diameter dilator tip 202 of FIG. 11 in an expanded-diameterconfiguration. For the sake of clarity, a flexible outer 240 surface hasbeen omitted from FIGS. 11 and 12 so that the internal structure can beobserved and described.

As shown in FIGS. 11 and 12, the delivery catheter 216 extends distallyfrom the distal end 214 of the dilator tip 202. At least one biasingmember 242 is disposed within the center of dilator tip 202 and canextend longitudinally from the proximal end 212 to the distal end 214 ofthe dilator tip 202. In one example, the biasing member 242 is a coilspring. One or more collars 244 may extend circumferentially around andcrimp down the proximal and distal ends 212, 214 of the dilator tip 202and a hub 246 may be secured to the collar 244.

Extending around the biasing member 242 between the proximal and distalends 212, 214 of the tip 202 is an expandable and contractible structure248. The structure 248 may be comprised of one or more fingers, wires,coils, fabrics, fibers, flexible arcuate members, cages, screens, disks,walls and the like, and may be constructed or formed from a singlematerial or, alternatively, may be formed from a variety or combinationof materials. In one example, at least a portion of structure 248 may beformed of any suitable material that may be expanded, such as bymechanical expansion. In other examples, at least a portion of thestructure 248 may be formed from any suitable material that will resultin self-expansion, such as shape memory material. As shown in FIGS. 11and 12, the structure 248 is a mesh. A flexible outer surface or member240 (shown in FIGS. 9 and 10 but removed from FIGS. 11, 11A and 12) maycover the mesh structure 248.

Dilating tip 202 can be mechanically expanded and contracted such thatthe outer diameter of the dilating tip 202 can increase and decrease.Such radial outward expansion of the tip 202 may be achieved in severalways. First, in one example, one or more resilient inner centralelongate member(s) 242 extends between the proximal and distal hubs 246as shown in FIGS. 11 and 12. The central elongate member 242 may includea coiled member or spring that extends substantially along thelongitudinal axis. A proximal end of the elongate member 248 may besecured to the proximal hub 246 and a distal end of the elongate membermay be secured to the distal hub 246.

The mesh structure 248 extends radially outwardly at a location that isgenerally centered between the respective hubs 246 to form asubstantially conical, elliptical, ovoidal or egg-shape. The elongatemember 248 may be biased in either an expanded condition or a contractedcondition, thereby biasing the tip 202 in either a diameter-reducedcondition or a diameter-expanded configuration, respectively. Theelongate member 248 is also preferably longitudinally extensible suchthat it can be lengthened or stretched to facilitate a radiallyconstricted reduced-diameter configuration as shown in FIG. 11. When therespective hubs 246 are extended away from each other in substantiallyopposing directions, the central elongate member 242 is extended. As aresult, the dilator tip 202 becomes radially inwardly contracted. Whenthe respective hubs 246 are moved towards each other, the centralelongate member shortens. As a result, the dilator tip 202 becomesradially outwardly expanded as shown in FIG. 12.

In another example, as shown generally in FIG. 11A, radial outwardexpansion of the dilator tip 202 may be achieved by providing twoseparate inner central elongate members, namely proximal elongate member242 a and distal elongate member 242 b coupled to each of the respectivehubs 246. The two central elongate members 242 a and 242 b may be in theform of springs or coils, or alternatively, two correspondingly shapedthreaded members, one of which is configured to receive the other in athreadedly engaging manner. The two elongate members 242 a and 242 bpreferably extend from each of the respective hubs 246 towards eachother to a point where their respective terminating ends are adjacentand/or abut, and are capable of otherwise engaging each other. One ofthe elongate members 242 b extending from the distal hub 246 may berotated relative to the other elongate member 242 a. Such rotation maybe achieved by rotation of the delivery catheter 216 by the user, which,in turn, causes rotation of the distal elongate member 242 b. Rotationof the distal elongate member 242 b causes the two elongate members toengage each other (such as by one elongate member threadedly engagingthe other elongate member) which, in turn, pulls the respective hubs 246towards each other along the longitudinal axis. As the hubs 246 arepulled towards each other, the woven mesh 248 becomes extended radiallyoutwardly at a location generally between the respective hubs 246 toform a radially outwardly expanded-diameter dilator tip 202 asillustrated in FIG. 12. Similarly, rotation of distal elongate member242 b (such as by rotation of the delivery catheter 216 in the oppositedirection) causes the elongate members 242 a and 242 b to unthread orotherwise disengage, thus moving the respective hubs 246 longitudinallyaway from each other, such that dilator tip 202 may be returned to aradially-inwardly reduced-diameter configuration, as illustrated inFIGS. 11 and 11A. Expansion and contraction of the variable diameter tip202 is further described in U.S. application Ser. No. 14/293,536, whichis incorporated by reference herein.

In yet another example, FIG. 13 illustrates an introducer 300 that canbe tracked into place within a vessel for delivery and deployment of abranched and/or fenestrated stent graft. The stent graft may be trackedinto place and also pre-cannulated by the use of only a single wire.This may be achieved by utilizing an adaptation of a “cartridge”technique. This technique may be performed using a peel-away introducersheath. FIG. 13 shows an example of an introducer 300 with a peel-awayintroducer sheath 304 for delivering and deploying a stent graft 310using an adapted cartridge technique.

A guide wire 306 can first be inserted percutaneously into a patient'svasculature via a needle by known techniques. A delivery sheath 316,coaxial with a dilator of sufficient size 303, can be tracked over theguide wire 306 to the desired location in the vessel. The dilator 303may have a nose cone 308 at its proximal end to provide an atraumatictip for navigating the dilator 303 to a desired location within avessel. The dilator 303 with the nose cone 308 at its proximal end canthen be removed from the vasculature, leaving the sheath 316 in place.Sheath 316 can then serve as a conduit through which introducer 300 canbe inserted.

A stent graft 310, loaded on the proximal end of a delivery catheter 302and constrained under a peel-away sheath 304, can then be inserted inand through a hemostatic valve (not shown) near the distal end (notshown) of the delivery sheath 316 and pushed forward or proximallythrough the delivery sheath (such as by a pusher catheter 305) to theintended deployment location within a patient's vasculature. Once there,a user can push the stent graft proximally and out of the proximal endof the peel away sheath 304 using pusher 305, or alternatively, the usermay remove the peel-away sheath 304 (distally) from the stent graft 310by using the ends 312 of the peel-away sheath 304 as handles and pullingthem distally so that the peel-away sheath 304 separates longitudinallyand splits at the distal end 314. Next, a user can then distally pull(withdraw) the pull-away sheath 304 allowing the stent graft 310 toradially outwardly expand and deploy within the vessel.

Thus, when the stent graft 310 (loaded on the delivery catheter 302within the peel-away sheath 304) is inserted through the delivery sheath316 that has already been tracked into place within the vessel, a secondguide wire and dilator tip may be eliminated. In other words, thedelivery sheath 316 provides a conduit through which the deliverycatheter 302 may be inserted, thus, the need for another wire and/ordilating tip may be unnecessary. Alternatively, the introducer 300 maycomprise a stent graft 310 (such as a branched stent graft 34 or afenestrated stent graft 78 as described above) that is pre-loaded with awire 318 so that once the stent graft 310 has been tracked to thedesired location within a vessel and removed from the peel away sheath304, the wire 318 may be manipulated by the user to cannulate one ormore branch vessels extending from the main vessel 1.

In one example, the introducer assembly 300 is used in the aortic arch.The stent graft may be a singular tube, a fenestrated stent graft or abranched or bifurcated stent graft. The wire 318 can be passed through abranch or fenestration of the stent graft 310 as generally describedabove. Once the stent graft 310 is deployed, the guide wire 318 will bein place to perform any necessary cannulation of a branch vesselextending from the main vessel. In this way, the introducer 300 can betracked into place within delivery sheath 316 and the stent graft branchand/or fenestration may also be pre-cannulated by the use of only asingle wire.

In yet another example, FIG. 15 illustrates the proximal end of adelivery device or introducer assembly that can be tracked into placewithin a vessel to deliver and deploy a pre-cannulated branched and/orfenestrated stent graft. The wire used to track the device into placemay be the same wire that is used to pre-cannulate the stent graft aswell as the wire used to cannulate a branch vessel extending from themain vessel, as will be described in further detail below. The deliverydevice or introducer assembly may, in one example, be like that shown inFIG. 8, for delivering a prosthesis such as stent graft 34, 78 and/or224 described above, or may be any other suitable introducer assemblychosen by one of skill in the art for use in a procedure.

The introducer may be pre-loaded with a guide wire that may be used totrack the introducer into place within a vessel, with the same guidewire also pre-cannulating a side branch and/or fenestration formed inthe stent graft. In other words, introduction of the introducer andcannulation of the internal graft branch or fenestration may be combinedthrough the use of a single guide wire, and this same guide wire maythen be further manipulated during use to cannulate one or more branchvessels extending from the main vessel 1, including but not limited tothe innominate artery 10, the left carotid artery 12 and/or the leftsubclavian artery 14.

FIG. 15 shows an example of an introducer assembly 400 for deliveringand deploying a stent graft 404. In FIG. 15, an introducer sheath 402has been partially retracted, allowing the proximal end of the stentgraft 404 to be exposed. The proximal end 438 of the stent graft 404 isreleasably coupled to the introducer, and in FIG. 15, the proximal end438 of the stent graft is retained in a radially inwardly contracteddelivery configuration by one or more proximal fixation mechanisms ordiameter reducing ties as will be described in further detail below. Thedistal end of the stent graft 404 may also be coupled to the introducer,and if desired, the stent graft 404 may be coupled to the introducer atone or more additional points along the main body of the stent graftbetween the proximal and distal ends.

Delivery of the stent graft 404 to the targeted location within a vesselcan be accomplished using a single guide wire. A guide wire 406 canfirst be inserted percutaneously into a patient's vasculature via aneedle by known techniques. Next, the introducer assembly 400 caninserted into the patient's vasculature and tracked over the guide wire406. Alternatively, the introducer assembly 400 can be inserted over theguide wire simultaneously with the guide wire 406 being tracked intoplace within a vessel.

An introducer sheath 402, coaxial with a stent graft 404 coupled to theproximal end of a delivery catheter 412 (and constrained under sheath402) can be tracked over the guide wire 406 (through delivery catheter412) to the intended deployment location within a patient's vasculature.The introducer sheath 402 may extend proximally over the stent graft 404to the distal end 440 of a nose cone dilator 408. The nose cone dilator408 may have a tapered atraumatic proximal tip for navigating to adesired location within a vessel. Once there, a user can then distallyretract the sheath 402, thus allowing the stent graft 404 to radiallyoutwardly expand and at least partially deploy within the vessel. Aftersheath retraction, the proximal end of the stent graft 404 may still bereleasably coupled to the delivery catheter 412 by the tri-fold proximalfixation mechanism 446 (as well as one or more additional points betweenthe proximal end and distal end of the stent graft may also still bereleasably coupled to the delivery catheter 412) as described below.

The stent graft 404 may comprise a branched stent graft 34 or afenestrated stent graft 78 as described above, or may be any other stentgraft configuration as necessary or desired depending on the particularvessel(s) being treated and the procedure being performed. For exemplarypurposes, the stent graft 404 as described further below is identifiedas a branched stent graft having an internal side branch 414, but itwould be recognized that the stent graft 404 may be any of theabove-mentioned configurations or combinations thereof. The stent graft404 may be pre-loaded with the guide wire 406, so that once the stentgraft 404 has been tracked to the desired location within a vessel, theguide wire 406 may be manipulated by the user to cannulate one or morebranch vessels extending from the main vessel. In one example, theintroducer assembly 400 may be used to deliver a stent graft into theaortic arch and the branch vessel extending from this main vessel 1 maybe the left subclavian artery 14, for example. The guide wire 406 can bepassed through the lumen of a side branch (such as internal branch 414)and/or fenestration (such as aperture 424) of the stent graft 404 asgenerally described above. Once the stent graft 404 is deployed, theguide wire 406 will be in place to perform any necessary exchangesincluding cannulation of a branch vessel extending from the aortic arch.In this way, the guide wire 406 advantageously serves as a means totrack the introducer assembly 400 to a desired location within thevessel 1 while also pre-cannulating the internal branch 414 or aperture424 of the stent graft 404 with a single guide wire 406. In other words,introduction of the introducer assembly and cannulation of the internalgraft branch (or fenestration) may be combined through the use of asingle guide wire 406, and this same guide wire may then be furthermanipulated during use to cannulate one or more branch vessels extendingfrom the main vessel.

As partially shown in FIG. 15, stent graft 404 has been partiallydeployed because introducer sheath 402 once constraining it has beenpartially withdrawn, allowing the proximal end 438 of stent graft 404 tobe unconstrained from the sheath 402. In this example, stent graft 404is a branched stent graft having a series of self-expanding stents 416extending along the length of the graft body 426. In this example, thebranch 414 is an internal branch. In other words, the body 420 of thebranch 414 extends within the lumen 422 of the stent graft 404. Thebranch 414 has a proximal end 418 with a proximal opening 432 thatextends from an aperture 424 formed in the sidewall of the graft body426 and has a distal open end 428 that opens into lumen 422 of the stentgraft 404.

As shown in FIGS. 15 and 25, the stent graft 404 carried by theintroducer assembly 400 can be pre-loaded with the guide wire 406. Inone example, the guide wire 406 can extend proximally through the lumen422 of the stent graft 404, into the distal end 428 of the internalbranch 414 and exit out of the branch 414 at the proximal branch opening432. The proximal tip 434 of the guide wire 406 can extend through achannel or lumen (not shown) in the dilator 408. As shown in FIG. 25,the proximal tip 434 of the guide wire 406 can, in use, be proximallyadvanced all the way out of the proximal end 436 of the dilator 408.

FIGS. 17 and 24 illustrate the introducer assembly 400 of FIG. 15 whenthe introducer sheath 402 has been fully retracted by a user, but thestent graft 404 is not yet fully deployed because the proximal end 438of stent graft 404 is still releasably attached or coupled to thedelivery catheter 412 by one or more proximal attachment mechanismsand/or diameter reducing ties. In one example, as illustrated in FIG.16, the proximal end 438 of stent graft 404 is releasably coupled ortied to the delivery catheter 412 at the distal end 440 of the dilator408 and/or at the proximal end 452 of the delivery catheter 412. In oneexample, the proximal end 438 of stent graft 404 is tied to the deliverycatheter 412 using at least two wires (first wire 442 and second wire444) to create a proximal tri-fold 446 in the graft body 426. Inaddition to the proximal attachment, the stent graft 404 may also bereleasably coupled or tied to the delivery catheter 412 at one or moreadditional points along the graft body 426 of the stent graft 404between the proximal end 438 and distal end.

The delivery catheter 412 may be stiff enough to allow it to be pushedwithin a vessel lumen without collapsing, yet resilient or otherwiseflexible enough to navigate the tortious vasculature. The deliverycatheter 412 may be substantially straight or it may have a curveimparted to at least a portion of it. For example, as shown in FIGS. 15,16, 24 and 25, the proximal end 452 of the delivery catheter 412 may bebendable to conform to the curve of the aorta as it is tracked intoplace. Alternatively, the proximal end 452 of the delivery catheter 412may be pre-curved so that it automatically conforms to the curve of theaortic arch 6 during delivery and deployment. As will be described infurther detail below, and as shown in FIGS. 16, 24 and 25, the deliverycatheter 412 extends through at least a portion of the stent graft lumen422 and exits the lumen 422 through the proximal branch opening 432. Theproximal end 452 of the delivery catheter 412 then extends throughaperture 424 and runs along the outside or external surface of the graftbody 456 adjacent a first point 466 at the proximal end of the stentgraft 404 as shown generally in FIGS. 16 and 19.

With the delivery catheter 412 having a curve imparted to at least aproximal end or portion of it, the delivery catheter thereby tends tosit adjacent to or on the greater curve of the aorta as shown in FIGS.24 and 25. In other words, the proximal end 452 of the delivery catheterthat runs along the outside surface of the graft body 456 and adjacentto a first point 466 at the proximal end of the stent graft 404 may besandwiched between the outer surface of the graft body and the innersurface of the vessel wall within the aorta when then stent graft 404 isunsheathed during delivery and deployment, as shown in connection withFIG. 25. With the stent graft 404 properly aligned with any one or moreof the desired branch vessel(s), and with the stent graft 404 releasablyattached to the delivery catheter at the proximal end 438 (and/orattached at any one or more points along the graft body 426 between theproximal and distal ends of the stent graft 404), the stent graft 404will preferably open away from the delivery catheter 412 (i.e., thestent graft 404 will expand downwardly and away from the deliverycatheter 412). Because the delivery catheter 412 extends along thegreater curve of the vessel, the delivery catheter 412 serves as a“spine” for the stent graft 404, to thereby maintain the position of thestent graft 404 (and the position of the internal branch 414, theaperture 424 and/or proximal branch opening 432) and properly align thestent graft 404 with the greater curve of the vessel as it is unsheathedduring deployment, further guaranteeing proper orientation of the stentgraft 404 within the vessel. Advantageously, with the delivery catheter412 serving as a “spine” that is releasably attached to at least theproximal end 438 (and which may also be releasably attached to one ormore additional points along the graft body 426) maintains or assuresrotational alignment of the stent graft 404, ultimately facilitatingalignment with and/or cannulation of the one or more branch vesselsextending from the main vessel 1, including but not limited to the leftsubclavian artery 14. Full deployment of the stent graft 404, includingrelease of the one or more proximal attachment mechanisms or wires isdescribed in further detail below.

FIGS. 17-21 illustrate a series of method steps in which at least twowires may be manipulated to tie and releasably couple the proximal end438 of graft body 426 into the tri-fold configuration 446 shown in FIG.16. As seen in FIG. 17, first wire 442 has a proximal end 448 and secondwire 444 has a proximal end 450. The first wire 442 and second wire 444may be disposed within the lumen of the delivery catheter 412 and mayextend proximally from the distal end (not shown) of the deliverycatheter 412 and exit the proximal end 452 of delivery catheter 412through one or more holes or apertures 454 formed in the deliverycatheter 412.

In one example, first wire 442 and second wire 444 exit the proximal end452 of delivery catheter 412 just distal to the distal end 440 ofdilator 408. The proximal end 448 of first wire 442 and the proximal end450 of second wire 444 may be threaded from the apertures 454 at alocation outside of graft body 456, threaded through graft body 426 atthe proximal end 438 of the stent graft 404 and into the lumen 422 ofthe stent graft, as shown in FIG. 17. Next, as seen in FIG. 18, firstwire 442 may be threaded from the inside of graft body 458 through thegraft body 426 at a second location or point 462 to outside of the graftbody 456. In one example, first wire 442 may be threaded through thegraft body 426 at a second location or point 462 that is approximatelyone-third of the circumference around the proximal end 438 of stentgraft 404 from the first point 466. Next, first wire 442 may be threadedback into the lumen 422 inside of the graft body 458 at or near thesecond point 462. Similarly, the second wire 444 may be threaded fromthe inside of graft body 458 through the graft body 426 to the outsideof the graft body 456. In one example, second wire 444 may be threadedat a third point or location 464 approximately two-thirds of thecircumference around the proximal end 438 of stent graft 404 (or, inother words, the third point 464 is circumferentially spaced from thefirst point 466 in one direction and from the second point 462 in theopposite direction. Next, second wire 444 may then be threaded back intothe graft body near the third point 464 to the inside of graft body 458as shown in FIG. 18.

As seen in FIGS. 19 and 20, the proximal ends 448, 450 of the first wire442 and second wire 444, respectively, are now both located within thestent graft lumen 422 and may be pulled taut to draw the graft body 426radially inwardly towards the delivery catheter 412 from the twolocations or points 462, 464 where the first wire 442 and second wire444 were threaded through the graft body 426. This creates multiple“lobes” or “folds” of fabric at the proximal end 438 of the stent graft404. As shown in FIG. 16, at least three lobes or folds 460 are formed,including at least a first fold, a second fold and a third fold when thewires 442 and 444 are pulled taut. As also shown in FIG. 16, theproximal end 452 of the delivery catheter 412 runs along the outside ofthe graft body 456 adjacent a first point 466 at the proximal end of thestent graft 404, thus, when the first and second wires 442, 444 arepulled taut, the second and third points 462, 464 of the stent graft arepulled towards and against the delivery catheter 412, while the deliverycatheter 412 presses against a first point 466, thus drawing the first,second and third points 466, 462, 464 respectively, inwardly towardseach other to pinch the proximal end 438 of the stent graft 404 into thetri-fold configuration 446.

In one example, the first wire 442 and the second wire 444 can extendlongitudinally from the external handle portion of the introducerassembly 400 and then be woven through the stent graft to form theproximal attachment as described above. In one example, the first wire442 and second wire 444 can be pulled taut by threading the proximalends 448, 450 of the respective wires back through the center of thegraft lumen and/or of the delivery catheter to extend distally back tothe user so that the user can pull distally on the proximal ends 448,450 of the respective wires to pull them taut. In other words, after thewires are woven through the graft fabric as shown in FIGS. 18-21, theymay be tightened or otherwise pulled taut from the handle portion of theintroducer so that the graft is pulled radially inwardly to create thetri-fold, and retained in that configuration until release is desired.

In another example, with the first wire 442 and second wire 444releasably coupled to the graft in a manner previously described (suchas in the tri-fold configuration, for example), the proximal ends 448,450 of the respective first wire 442 and second wire 444 may extendproximally into the distal end of the nose cone dilator 410 and beretained or held in that position within the nose cone dilator 410 byvarious releasable attachment means including friction fit, adhesivesand the like. The distal ends of the first and second wires 442, 444 mayextend distally to the handle portion of the introducer and bemanipulated by the user to pull the respective wires taut, thus holdingthe proximal end of the stent graft 404 in a constrained configuration.Release of the respective first and second wires 442, 444 to release theproximal end of the stent graft 404 may be accomplished by the usermanipulating one or more release mechanisms or knobs on the handle 200of the introducer during deployment.

FIGS. 21 and 22 illustrate how the lobes or folds 460 formed at theproximal end 438 of the graft body 426 may be folded or wrappedcircumferentially around the delivery catheter 412 to reduce thediameter of the proximal tri-fold 446. More specifically, once the firstwire 442 and the second wire 444 have been pulled taut and the graftbody 426 has been pulled radially inwardly towards the delivery catheter412 at the first, second and third points 466, 462, 464, respectively,the multiple lobes or folds 460 may be folded down and wrapped upon eachother, in either a clock-wise or counter clock-wise direction in afan-blade or pin-wheel-like configuration as shown in FIGS. 21 and 22.The inner surface of one lobe 460 lies down upon the outer surface ofthe adjacent lobe 460 thereby wrapping the proximal end 438 of the stentgraft radially inwardly around and against the delivery catheter 412. Inone example, the three folds include a first fold, a second fold, and athird fold, wherein the first fold at least partially overlies thesecond fold, the second fold at least partially overlies the third fold,and the third fold at least partially overlies the first fold. Further,in another example, the first fold and the second fold may at leastpartially directly overlie the delivery catheter and the third fold mayat least partially indirectly overlie the delivery catheter.

In this arrangement, the sheath 402 can extend proximally over the stentgraft 404 to the nose cone dilator 408, so that the introducer assemblyis in a reduced-diameter low profile delivery configuration.

One of skill in the art would recognize that a single wire may be used(rather than two wires 442, 444) to weave in and out of the graft fabricto create a tri-fold configuration 446. Alternatively, one or more wiresmay be used to create a bi-fold or other diameter reducing fixationarrangement at the proximal end 438 of the stent graft 404 to allow theproximal end 438 to be releasably coupled to the delivery catheter,including but not limited to various wire weaving patterns and variousattachment mechanisms for securing the wire to the stent graft 404 andto the delivery catheter 412.

FIGS. 23-25 illustrate various steps in one exemplary method forintroducing and deploying a stent graft within a vessel using theintroducer assembly 400. For example, as illustrated in FIG. 23, theintroducer assembly 400 is tracked over guide wire 406 (through thelumen of the delivery catheter 412 and through the channel or lumenextending through the nose cone dilator 408) to a location within avessel 1, with the stent graft (not shown) still covered and held in aradially inwardly contracted delivery configuration by introducer sheath402. The sheath 402 may then be distally retracted as shown in FIG. 24,allowing the stent graft 404 to at least partially deploy from theintroducer assembly 400 and become partially expanded within the vessel1 at the site of the aneurysm 16.

As previously mentioned, the delivery catheter 412 may have a curveimparted to at least a proximal end or portion of it, and the deliverycatheter thereby tends to sit adjacent to or on the greater curve of theaorta as shown in FIGS. 24 and 25. As such, the stent graft 404 willpreferably open away from the delivery catheter 412 (i.e., the stentgraft 404 will expand downwardly and away from the delivery catheter) asit is unsheathed during deployment, further guaranteeing properorientation within the vessel. The delivery catheter 412 may thus besandwiched between the outer surface of the stent graft 404 at theproximal end of the stent graft and the inner surface of the vesselwall, while facilitating alignment of the stent graft 404 within thevessel 1 as well as alignment with one or more branch vessels extendingfrom the main vessel 1. As illustrated in FIG. 24, the proximal end 438of stent graft 404 is still coupled to the delivery catheter 412 bywires 442, 444, which hold the proximal end 438 in the tri-foldconfiguration 446 after the sheath 402 has been distally retracted.

Next, as shown in FIG. 25, while the introducer assembly 400 remainswithin the vessel 1, and the first wire (not shown) and second wire (notshown) have been released so that the proximal end 438 of the stentgraft 404 is no longer constrained radially inwardly to the deliverycatheter 412 by the proximal tri-fold shown in FIG. 16. Once the stentgraft 404 has been fully released from the delivery catheter 412, theuser may distally retract the delivery catheter 412 (with the nose conedilator 408 at the proximal end thereof) and withdraw it from thevessel. The guide wire 406 may remain in place within the vessel, suchthat it extends proximally through the lumen 422 of the stent graft 404,into the distal open end 428 of the internal branch 414, through thebody 420 of the branch and out of the stent graft 404 through theproximal opening 432 at the proximal end 418 of the internal branch 414to a location external of the graft body at the proximal end of thestent graft 404. In this way, a portion of the guide wire 406 extendingproximally from the aperture 424 formed in the sidewall of the graftbody is sandwiched between the outside surface 456 of the graft body 426and the inside surface of the vessel wall. The guide wire may bemanipulated by the user to extend the guide wire 406 into a branchvessel, such as the left subclavian artery 14, to cannulate this branchvessel with the guide wire 406.

At this time, if necessary and desired, a second delivery system (notshown), which may include a second delivery sheath with a bridging stent(not shown) may be extended over the guide wire 406 and tracked into thebranch vessel, such as the left subclavian artery 14. The bridging stentmay be deployed and the second delivery system removed from thevasculature. The deployed bridging stent (not shown) then extends fromthe proximal end 418 of the internal branch 414, through the aperture424 formed in the sidewall of the graft body 426 and into the branchvessel to restore patency to the vessel.

In an alternative embodiment, as illustrated in FIG. 26, the introducerassembly 400 may be provided with a delivery catheter having arelatively smaller diameter nose cone dilator 500 at the proximal endthereof. The relatively smaller diameter nose cone dilator 500 may besized and shaped so as to minimize the risk of the nose cone dilator 500catching on any portion of the stent graft 404 as the delivery catheterand nose cone dilator 500 are distally retracted around the proximal end438 of the stent graft 404 and through the lumen 422 of the stent graft404 (and/or retracted through any aperture 424 or internal side branch414) during removal from the vasculature. A delivery sheath 502 havingan inwardly tapered proximal end may be provided to mate with the nosecone dilator 500. In one example, the relatively smaller diameterdilator 500 may be between about 8 Fr and about 16 Fr. The tapereddelivery sheath 502 is tapered radially inwardly at the proximal end 504to mate with the nose cone dilator, and is constructed of a deformable,expandable and/or elastic material, and/or a material that can be easilytorn, and/or has folds in the material such that it can be contractedand expanded. As such, the tapered delivery sheath 502 can deform as itis distally retracted over the stent graft 404, therefore accommodatingthe larger outer diameter of the various other components of theintroducer assembly 400 as the sheath slides distally by the user duringdeployment. FIG. 26 shows one example of a relatively smaller diameterdilator 500 and a tapered delivery sheath 502.

In an alternative example, the proximal end 438 of the stent graft 404may comprise a slit, hole, opening or pocket (not shown) formed withinthe wall of the graft body 426 that is located in front of (proximal of)the branch proximal end 418 at a point approximately where the proximalattachment wires 442 and 444 extend through the graft (refer to FIG.17). The nose cone dilator 408 and delivery catheter may then extendfrom the outer surface of the graft body, through the slit, hole orpocket and back into the lumen 422 at the proximal end 438 of the graft.In other words, the proximal end 452 of the delivery catheter wouldextend out of the proximal branch opening 432 and extend proximally onand along a portion of the outside surface at the proximal end 438 ofthe graft. Then, instead of continuing along the outer surface of theproximal end 438 of the stent graft 404 as shown in FIGS. 15 and 16, thenose cone dilator 410 and delivery catheter 412 would then extend backinto the graft lumen 422 through this slit, opening or pocket.

While various embodiments of the invention have been described, theinvention is not to be restricted except in light of the attached claimsand their equivalents. Moreover, the advantages described herein are notnecessarily the only advantages of the invention and it is notnecessarily expected that every embodiment of the invention will achieveall of the advantages described.

We claim:
 1. A prosthesis delivery device comprising: a deliverycatheter having a proximal end, a tubular prosthesis releasably coupledto the proximal end of the delivery catheter, wherein the prosthesis hasa proximal end, a distal end, a lumen extending between the proximal endand distal end, a sidewall of graft material, an inner graft surface, anouter graft surface, and a fenestration formed in the sidewall of theprosthesis, wherein the delivery catheter extends proximally through atleast a portion of the prosthesis lumen and through the fenestration toa location external of the prosthesis and adjacent a first point on theouter graft surface of the graft at the proximal end, a first proximalattachment mechanism releasably coupling a second point on the proximalend of the prosthesis to the delivery catheter, wherein the second pointis circumferentially spaced from the first point; a second proximalattachment mechanism releasably coupling a third point on the proximalend of the prosthesis to the delivery catheter, wherein the third pointis circumferentially spaced from the first point in one direction andfrom the second point in the opposite direction; wherein the first andsecond proximal attachment mechanisms draw the second and third pointsto the first point to form three folds of graft fabric; wherein thefolds extend about the delivery catheter in a folded configuration suchthat the outer surface of the graft at least partially wraps around thedelivery catheter.
 2. The prosthesis delivery device of claim 1, whereinthe three folds include a first fold, a second fold, and a third fold,wherein the first fold at least partially overlies the second fold, thesecond fold at least partially overlies the third fold, and the thirdfold at least partially overlies the first fold.
 3. The prosthesisdelivery device of claim 1, wherein the three folds include a firstfold, a second fold, and a third fold, wherein the first fold at leastpartially directly overlies the delivery catheter, the second fold atleast partially indirectly overlies the delivery catheter, and the thirdfold at least partially indirectly overlies the delivery catheter. 4.The prosthesis delivery device of claim 1, wherein the three foldsinclude a first fold, a second fold, and a third fold, wherein the firstfold at least partially directly overlies the delivery catheter, thesecond fold at least partially indirectly overlies the deliverycatheter, and the third fold at least partially overlies the first fold.5. The prosthesis delivery device of claim 1, wherein the foldedconfiguration is a spiral configuration.
 6. The prosthesis deliverydevice of claim 1 wherein the first and second attachment mechanismseach comprise a loop of wire, suture, filament or thread that extends atleast partially through the lumen of the delivery catheter to arespective second or third point on the proximal end of the prosthesis.7. The prosthesis delivery device of claim 6 wherein the deliverycatheter comprises a first opening and a second opening formed in asidewall thereof, and wherein the first attachment mechanism extends outof the lumen of the delivery catheter through the first opening andwherein the second attachment mechanism extends out of the lumen of thedelivery catheter through the second opening.
 8. The prosthesis deliverydevice of claim 1 wherein the second point is spaced in a firstdirection one-third about the circumference of the prosthesis from thefenestration, and wherein the third point is spaced in a seconddirection one-third about the circumference of the prosthesis from thefenestration.
 9. The prosthesis delivery device of claim 1 wherein thethree folds of graft fabric are circumferentially folded upon eachother.
 10. A prosthesis delivery device comprising: a delivery catheterhaving a proximal end, a tubular prosthesis releasably coupled to theproximal end of the delivery catheter, wherein the prosthesis has aproximal end, a distal end, a lumen extending between the proximal endand distal end, a sidewall of graft material, an inner graft surface, anouter graft surface, and a fenestration formed in the sidewall of theprosthesis, wherein the delivery catheter extends proximally through atleast a portion of the prosthesis lumen and through the fenestration toa location external of the prosthesis and adjacent a first point on theouter graft surface at the proximal end of the prosthesis; a firstproximal attachment mechanism releasably coupling a second point on theproximal end of the prosthesis to the delivery catheter, wherein thesecond point is circumferentially spaced from the first point; a secondproximal attachment mechanism releasably coupling a third point on theproximal end of the prosthesis to the delivery catheter, wherein thethird point is circumferentially spaced from the first point in onedirection and circumferentially spaced from the second point in theopposite direction; wherein the first and second proximal attachmentmechanisms draw the second and third points to the first point to formfirst, second, and third folds of graft fabric; wherein the folds extendabout the delivery catheter in a folded configuration.
 11. Theprosthesis delivery device of claim 10, wherein the first fold at leastpartially overlies the second fold, the second fold at least partiallyoverlies the third fold, and the third fold at least partially overliesthe first fold.
 12. The prosthesis delivery device of claim 10, whereinthe delivery catheter extends proximally from the fenestration formed inthe sidewall of the prosthesis along an outer surface of the prosthesissidewall.
 13. The prosthesis delivery device of claim 10, wherein thethree folds include a first fold, a second fold, and a third fold,wherein the first fold at least partially directly overlies the deliverycatheter, the second fold at least partially indirectly overlies thedelivery catheter, and the third fold at least partially indirectlyoverlies the delivery catheter.
 14. The prosthesis delivery device ofclaim 10, wherein the three folds include a first fold, a second fold,and a third fold, wherein the first fold at least partially directlyoverlies the delivery catheter, the second fold at least partiallyindirectly overlies the delivery catheter, and the third fold at leastpartially overlies the first fold.
 15. The prosthesis delivery device ofclaim 10, wherein the folded configuration is a spiral configuration.16. The prosthesis delivery device of claim 10 wherein at least aportion of the delivery catheter has a curve imparted to it.
 17. Theprosthesis delivery device of claim 16 wherein at least a portion of theprosthesis substantially conforms to the curve of the delivery catheter.18. The prosthesis delivery device of claim 10 wherein the deliverycatheter comprises at least one opening formed in a sidewall thereof,the at least one opening located closely adjacent the proximal end ofthe prosthesis; and wherein the first and second attachment mechanismsextends out of the lumen of the delivery catheter through the at leastone opening.
 19. The prosthesis delivery device of claim 10 wherein thedelivery catheter comprises a first opening and a second opening formedin the sidewall thereof; wherein the first attachment mechanism extendsfrom the first opening formed in the delivery catheter, through thesidewall of the prosthesis and into the prosthesis lumen, then extendsout of the prosthesis lumen through the second point at the proximal endof the prosthesis, then extends back through the prosthesis sidewallinto the prosthesis lumen, and wherein the second attachment mechanismextends from the second opening formed in the delivery catheter, throughthe sidewall of the prosthesis and into the prosthesis lumen, thenextends out of the prosthesis lumen through the third point at theproximal end of the prosthesis, then extends back through the prosthesissidewall into the prosthesis lumen.
 20. A prosthesis delivery devicecomprising: a delivery catheter having a proximal end, a tubularprosthesis releasably coupled to the proximal end of the deliverycatheter, wherein the prosthesis has a proximal end, a distal end, and alumen extending between the proximal end and distal end, and afenestration formed in a sidewall of the prosthesis, wherein thedelivery catheter extends proximally though at least a portion of theprosthesis lumen and through the fenestration formed in the sidewall ofthe prosthesis, a first attachment mechanism releasably coupling asecond point at the proximal end of the prosthesis to the deliverycatheter, a second attachment mechanism releasably coupling a thirdpoint at the proximal end of the prosthesis to the delivery catheter,wherein the first and second proximal attachment mechanisms have a firstconfiguration in which the proximal end of the prosthesis is coupled tothe delivery catheter and a second configuration in which the proximalend of the prosthesis is released from the delivery catheter.